Mill



Dec. 15, 1936.- J. A. GERVAIS MILL Filed June 20, 1955 Patented Dec. 15, 1936 UNITED STATES PATENT OFFICE MILL Application June 20, 1933, Serial No. 676,672

9 Claims.

My invention relates to a mill particularly adapted for crushing and/or grinding ores.

At the present time the crushing and stamping or grinding machinery set up at a mine is exceedingly cumbersome and heavy, is very expensive, and is characterized generally by permanence of installation and general immobility. Manysmall mines new remain unworked because the enormous expense of installing milling machinery might not be justified by the quantity of ore to be milled at that particular mine. Furthermore, many mines which would ordinarily yield satisfactory returns on the large investment required for the installation of milling machinery are so inaccessibly located that it is difficult and some-v times impossible to transport the milling machinery to such mines.

It is the general object of my invention to provide a simple, relatively inexpensive mill, which will serve the purposes of the much more expensive, relatively immobile, milling installations in use at the present time.

It is a more specific object to provide an improved crusher for ores and the like.

It is another object to provide an improved grinding mill for crushed ores, for reducing crushed ores in a simple and efficient manner.

It is still another object to provide a combined crushing and grinding device so arranged that the crusher discharges crushed material into a grinding throat where the crushed material is finely ground.

It is another object to provide a mill which may be constructed of separable, relatively light parts which may be easily transported to relatively inaccessible locations and, broadly speaking, it is an object to provide a mill of sturdy construction, relatively cheap to manufacture, not likely to get out of order, and which will efl1 ciently mill ores and thelike.

Briefly stated, in a preferred form of the invention when embodied in a combined crusher and grinder, I provide a casing or housing having relatively fixed and movable crusher parts for crushing ores and the like. Located adjacent the crusher and preferably beneath the same and rigidly securedthereto is a grinder, comprising relatively fixed and movable grinder elements, the intake of the grinding throat being located so as to receive the crushed'material from the crusher, so that mined orefed into the crusher will be crushed and immediately delivered into the grind-. er, where it is reduced to suitable size for further treatment for the recovery of the metal or metals originally contained in the ore.

lar casing, preferably made of separable sections The invention contemplates improvements in both a crusher and grinder, and the crusher and grinder may be advantageously used independently of each other. In the preferred form, however, the crusher and grinder are arranged in 5 tandem, so that mined ore may be fed in and the ground and finely powdered ore discharged.

A single prime mover, such as a Diesel engine or the like, may serve to drive the movable elements of both the crusher and grinder when the 10 latter are arranged in tandem.

The mill is preferably constructed of relatively small units which may be easily transported and assembled at the mine. The mill is of such simplicity and the arrangement and construction are such that the mill may be advantageously set up and used at small, inaccessible mines where it would be economically unsound to install the usual more elaborate and expensive milling machinery. The drawing, illustrating merely a preferred form of the invention, is a view in partial side elevation and partial central section of a mill embodying features of the invention.

The mill illustrated is a combination crushing and grinding mill, though, as indicated above, the invention contemplates various features of improvement in both the crusher and grinder, which features may be advantageously employed whether or not the mill embodies a combined 30 crusher and grinder.'

As illustrated, 5 indicates generally a crusher, While 6 indicates generally a grinder positioned therebeneath. The crusher is preferably supported by the grinder portion of the mill, and both in turn may be supported by the base 1, carried by concrete or other suitable foundation 8.

The crusher 5 may comprise a generally circu- 9-10, which may be circumferentially secured to each other by means of the flanges and through-bolts ll-l l. The circumferential sections 9-10 may in turn be radially divided and secured to each other by means of the radial flanges and through-bolts l2-l2. For very small mills or where transportation facilities are adequate the casing need not necessarily be made in sections.

To'the top of the casing section 9 is secured a flared feed chute section Him the reception of the mined ore.

The lower casing section It] may be supported on and be secured to a dividing or partition plate M, which in turn may rest upon the upper grinder mill casing section l5, said two sections Ill-l5 being secured to each other and to the partition plate M as by means of through-bolts IB-IS. The grinder casing may comprise circumferential sections I5-ll, the construction of which may correspond generally to the sections 9-l of the crusher heretofore described.

The grinder casing may be supported upon a bottom supporting or frame plate l8, to which it may be secured by means of through-bolts IS. The frame plate I8 may have an upstanding wall 18', forming a channel or trough around the grinder for the reception of the ground material, which is finally discharged through the disdicharge chute 20, as will be understood. The various casing sections and base plate I8 and parts carried thereby may be supported upon the lower frame casting 2i, which may in turn be carried by and secured to the foundation 8.

The frame casting 2|, which may be made in detachable sections, includes a housing and may contain gearing for driving the crusher and grinder parts, as will be described. Suitable openings (not shown) may be provided in the frame 2|, so as to permit access to the parts enclosed thereby.

The crusher is provided with relatively fixed and movable crusher elements, so that ore introduced between the fixed and movable elements will be crushed and the crushed fragments will pass downwardly into the grinder, as will be described.

In the form shown the fixed crusher member comprises 'a plurality of annular rings 22 of generally decreasing inside diameter toward the bottom, so that the series of rings 22-22 forms a generally funnel-shaped fixed crusher part or element. The rings 22, which may be formed of suitably hardened metal, may rest one upon the other and be secured between the partition plate i4 and the upper feed chute section l3, as will be clear from the drawing. The plates 22-22 may be keyed against rotation in the casing, as by means of one or more keys, such as 23. If desired the crushing surfaces of the rings 22-22 may be serrated or provided with irregular faces, such as the circumferentially-extending grooves 24, which will provide a generally corrugated effect and tend to hold the ore against slipping out of the generally funnel-shaped fixed grinder element when pressure is applied thereto by the movable pressure elements, to bedescribed.

The movable crusher means preferably comprises a plurality of movable members or parts, which are successively moved toward and away from the fixed grinder rings 22, and the movable crusher elements are preferably so arranged as to produce a generally wave-like action, whereby the ore will be progressively reduced in size. The mounting for. the movable crusher elements in the preferred form includes a central shaft 25, mounted at the top in a sturdy roller bearing or the like 26, for taking the relatively-heavy radial loads occasioned by the crushing action. The roller hearing may be supported by a central boss 2?, carried by and preferably integral with arms 28-28 extending therefrom to the main or outer portion of the chute casting I3. The arms 28 and central boss 21, constituting what may be termed a spider, are constructed so as to form ample openings or passageways between adjacent arms for the passage of ore of the size for which the mill is adapted. The shaft is supported radially at the lower portion of the crusher by means of a suitable bearing, such as the roller bearing 29, carried by a sleeve shaft 30 to be more specifically described, which sleeve in turn may be radially supported by means of a roller bearing 3|, in turn carried by the partition plate I4, as will be clear from the drawing.

The shaft 25 carries a plurality of eccentrics 32-32, which are preferably arranged in generally staggered relation, that is, the line of maximum eccentricity of one eccentric is at an angle to the line of maximum eccentricity of the next succeeding eccentric. The eccentrics are preferably keyed to 'and also rigidly secured against axial movement on the shaft.

Surrounding and driven by each eccentric is what may be termed a movable crusher ring 33, and each upper crusher ring may rest on and be carried by the next lower crusher ring. The lowermost crusher ring 34 may be similar to the upper rings 33 and have a bearing on the partition M. The crusher rings 33-34 may each be circularly splined to their respective eccentrics and be thus supported by the eccentrics.

The movable crusher rings 33-33, as well as the fixed crusher rings 22 are preferably formed with readily renewable crusher faces so as to facilitate and cheapen repair and renewal. The outer surfaces of the crusher rings 33-3 1 need not be concentric with their inner surfaces but may be eccentric thereto or of other form.

The moving surfaces between the eccentrics 32 and the crusher rings 33 may be lubricated, as by means of oil entering through the pipe or cored passage 35 and passing into a longitudinal bore 36 in the shaft, from which it issues through passages 31 extending transversely of the shaft and through each eccentric, preferably at the nonpressure side thereof, so as to facilitate the admission of the fluid to the bearing surfaces.

The shaft 25 may be provided with a second bore 38, extending through the top of the shaft, whichmay be enclosed by a dome or cover cap 39 and which is provided with a water connection 40, so that water or other washing fluid may be introduced under suitable pressure into the bore 38 and through suitable transverse openings H to the space between adjacent movable crusher rings, for the purpose of washing dust and other foreign matter out from between the contacting surfaces. rings 33-33 are preferably slightly cored out or relieved, so as to provide an adequate water reservoir or passage, in order to increase the tendency of the water to fiow out between all portions of the contiguous surfaces of the movable crusher rings 33. 'The water flowing out is of further advantage in wetting the crushed ore and assisting in subsequent grinding operations when the crusher and grinder are arranged in tandem.

The end thrust load of the shaft 25 and parts carried thereby may be taken by the ball thrust bearing 62, upon which the lower eccentric 33 rests.

The operation of the crusher thus far described is as follows:

The shaft 25 is rotated by means to be described. The eccentrics 32 will cause the movable crusher rings 33 to move (when there is ore resistance) with a generally planetary motion. that is, each portion of the crusher ring 33 will successively approach and recede from the adjacent fixed crusher surface 22. Conversely when there is no ore resistance opposed to any crusher ring, such ring will rotate with its eccentric until resistance is encountered. The ore pieces crushed The adjacent faces of the crusher by the upper crusher ring 33 will fall downwardly and, upon further rotation of the shaft 25, the next lower crusher ring 33 or one of the lower crusher rings 33 (depending upon the size to which each piece of ore is crushed by the first crusher ring) will crush, and the crushing in any particular generally vertical zone will be done with a substantially wave-like action, that is, due to the generally funnel-shaped crusher throat larger ore particles are crushed into successively smaller particles, until the ore reaches the throat between the last movable crusher ring 34 and the lower fixed crusher ring 22. The crusher rings last mentioned may be considered as sizing crusher rings to make sure that before the crushed ore passes from the crusher it will be substantially sized, or rather there will be an upper limit to the size of the crushed ore reaching the grinder.

Since each crusher ring is freely movablein a circumferential direction with its eccentric, the crushing action between any ring and the crusher surface may occur at different circumferential portions of said surface.

The crushed ore particles pass downwardly through suitable circumferentially extending passages or openings 43 in plate M, which are suflicient in number and extent to permit the passage of the crushed ore, and the webs defining the circumferential extent of the passages 43-43 are sufficiently numerous and of sufficient extent to not unduly weaken the partition plate [4 which, as heretofore indicated, partly carries the radial loads of the shaft through the roller bearings 29 and 3|.

The grinder section 6, as heretofore indicated. includes the casing I5l1, and within the casing there are fixed and movable grinder means. The

fixed grinder means may comprise a plurality of annular grinder disks 4444, the internal opening or bore in each disk preferably being larger than the next upper disk, and on the lowermost grinder disk 45 the grinding face may extend ment of the fixed grinder disks 44-45, so that the grinding pressure is produced in part by the weight of the grinder disks 4445. The grind-.

ing pressure may be produced or increased by other means such as springs.

The'movable or rotatable grinder disks 46-46 are carried by and keyed against rotation on the sleeve shaft 30 heretofore noted. The diameters of the disks 46-46 increase downwardly,in a manner generally complementary to the increase in diameter of the bore through the fixed grinder disks, in such manner that there is produced a tapered grinding throat 41, which tapered grinding throat decreases downwardly, and the lower movable grinding disk 48 is passed beneath the disk 45 in a manner to support the'same when there is no ore between those grinder surfaces. The weight of the movable grinder disks 464 8 may be supported by a thrust bearing 49 interposed between the lowermost disk 48 and the base plate or casting l8 heretofore noted.

The upper end of the sleeve shaft 30 carrying the movable grinder disks is supported radially by means of the roller bearing 3|, and may be be formed of abrasive material, so as to have a direct abrasive, rather than a crushing, action upon the ore being reduced. Some or all of the disks may, of course, be formed of hardened metal so as to reduce the size of the ore by the crushing action between the fixed and movable grinder disks. The grinder parts are preferably formed with readily renewable faces sov that as wear occurs or in case of breakage renewal or repair will be facilitated.

Thus, when the sleeve 36 is rotated by means to be described, the movable grinder disks 46-48 serve to grind the crushed material received in the throat through the passageways 43 in the partitionplate l4 and, since the grinding throat is progressively smaller as it reaches the discharge, the material being ground is progressive 1y ground finer and finer, and finally reaches the discharge chute 20 in its finely ground condition.

The water which was introduced centrally of the shaft 25 for the purpose heretofore described will flow with the crushed ore into the grinding throat and will assist in the grinding action and will carry away the finer particles during the grinding operation, so as to permit the grinding action to take place where it should on the larger particles. The ground ore may be discharged, depending upon the quantity of water supplied, in the form of a slurry or mud.

The grinder and crusher parts may be driven by means of 2. Diesel engine or other prime mover, and in the form shown the drive may be as follows:

A driven shaft 55 enters the base 'l and is provided with a worm 56, meshing with a worm gear 51 carried by the lower end of the shaft 25. The lower end of the shaft may be supported radially in any suitable manner, as by means of a roller bearing 58 in the lower skirt on the sleeve shaft 36. The worm or driven shaft 55 may be extended through the base casting 2| and be provided with inertia means, such as a heavy fly wheel 59, since, during the crushing operation, the shaft will be subjected to varying degrees of torque, and some inertia means, such as the fly wheel, will even out irregularities and permit the shaft 55 to be driven by a relatively constant source of power.

It will be seen that through the worm and worm wheel drive a powerful and relatively slow rotation is imparted to the shaft 25, so that the ore will be crushed and at the desired speed.

The grinding portion of the mill is preferably actuated at a considerably higher speed and, in the form shown, a drive shaft 66 enters the base casting 2land is provided with a bevel pinion 6|, meshing with a bevel gear 62, splined to or otherwise secured to the lower skirt on the sleeve shaft 30. Thus, if the shafts 55 and. 60 be driven at the same speed the grinder will be actuated at ahigher rate of speed than, the crusher. Obviously, the speeds. at' which the crusher and grinder are operated must be determined by the particular material being crushed or ground, the original size thereof, and the final desired size of the crushed material, and proper crushing and grinding speeds will be varied in, accordance with conditions. If desired, the two shafts '55 and 60 may be and preferably are be transmitted through reduction gearin'g, to impart to the shafts 55-60 the proper speeds.

Needless to say the various ball and roller bearings employed will be provided with suitable seals or housings to retain lubricant and exclude crushed ore or other foreign matter.

It will thus be seen that I have provided an exceedingly simple mill which may be embodied ii a combined crushing and grinding mill. It will also be seen that I have devised various features of improvement in both a crusher and a grinder, and that various features may be ad-.

vantageously employed independently of each rther.

While a preferred form of the invention has been described in considerable detail, it is to be understood that various changes, modifications, additions and omissions may be made within the scope of the invention as defined in the appended claims.

I claim:

l. A crusher comprising a casing, means having relatively fixed crusher surfaces within said casing, a shaft in said casing, a plurality of eccentrics carried thereby, and a movable crusher ring actuated by each said eccentric, and means for conducting oil to the surfaces of said eccentrics and means for forcing fluid outwardly between the crusher rings operated by said eccentrics.

2. In a crusher, an annular crusher surface, a shaft within said surface, a plurality of crusher rings mounted one above another upon said shaft, each ring being mounted for angular movement relative to one another about said shaft and movable relatively to one another toward and from said crusher surface, the surfaces of adjacent rings being slightly cored out or relieved, and means for ejecting fluid between adjacent crusher rings.

3. A crusher comprising an annular crusher surface, a vertical drive shaft concentrically disposed in relation to said surface, a plurality of superposed adjacent eccentrics carried by said shaft in staggered relation, a plurality of superposed adjacent crusher members each surrounding an eccentric and freely mounted thereon said eccentrics acting to move said crusher members relatively to each other towards and from said crusher surface.

4. A crusher for rock, ore and the like, having an annular crusher surface, a supporting shaft mounted within said surface, a plurality of superposed adjacent eccentrics arranged in staggered relation on said shaft and a plurality of crusher members one surrounding each eccentrio and freely movable thereon, said eccentrics acting to positively move a crusher member to cause crushing action between a member and any portion of said surface.

5. A crusher comprising an annular crusher surface, a drive shaft disposed within said surface, a plurality of superposed eccentrics mounted adjacent each other on said shaft in staggered relation, and a plurality of ring crusher members each surrounding an eccentric and freely movable on an eccentric.

6. In a crusher, a shaft, a plurality of adjacent superposed annular crusher members mounted thereon, a crusher surface surrounding said members and concentric with said shaft, each crusher member freely mounted for angular movement relative to said crusher surface when any member is unobstructed by the material to be crushed, and means for positively causing each crusher member individually to move relatively to one another radially in respect of said crusher surface to act with crushing action when said member is obstructed.

7. A crusher having a plurality of individual crusher members arranged one adjacent another on a supporting shaft in offset relation and each freely rotatable axially with its supporting shaft when unobstructed by the material to be crushed, and means to cause each crusher member individually to act with crushing movement and with substantially no rotary movement when an obstruction is met.

8. In crushing apparatus, the combination of a casing having a fixed tubular interior crushing surface of circular cross section; a vertical shaft extending longitudinally of and rotatable in the casing concentric with its crushing surface; and a plurality of superimposed cylindrical crushing members each eccentrically mounted on and positively driven by the said shaft for cooperation with the aforesaid crushing surface, the ecface; a plurality of superimposed eccentrics each secured to the shaft; and closely-fitting crushing rings rotatably mounted on the said eccentrics for cooperation with the aforesaid crushing surface, the eccentric throw of different eccentrics being in different angular positions in the plane of rotation.

JOSEPH ADRIEN GERVAIS. 

